The invention relates to an apparatus for use in manufacturing ophthalmic components and more particularly, to an apparatus for carrying molds used to form ophthalmic components.
The manufacture of ophthalmic components, for example contact lenses, is typically carried out in a large number of separate production steps. Contact lenses are generally manufactured in automated or semi-automated production processes. Lens molds including base curve and front curve mold halves are transported on carriers through the production process. The molds are fitted together to form a small crescent shaped mold cavity between the base curve and front curve molds. A lens is formed by introducing a monomer lens formulation in the front curve mold and then sandwiching the monomer between the base curve and front curve molds. The monomer is then polymerized through heat treatment, light treatment or other polymerizing process, thus forming a lens. The lens is then removed from the molds for further treatment and is packaged for consumer use.
Typically, a lens production process uses sets of two matching carriers. One carrier holds a multitude of base curve lens molds, and another carrier holds a matching number of front curve lens molds. The mold carriers are transported to different processing stations within the lens manufacturing process and subjected to different processing steps. For example, the mold carriers receive lens molds in proper positions and are closed and locked to form lenses. Once the lenses are formed, the closed carriers are opened to remove the lenses. Consequently, the carriers must be designed to be suitable for many different steps of the lens manufacturing process.
There remains a need for improved carriers that are highly suitable for a lens production process, especially a large-scale lens production process.
The invention provides a front curve lens mold carrier and a base curve lens mold carrier. The front curve lens mold carrier includes a front curve top plate and a front curve bottom plate attached to the top plate. The front curve bottom plate has a plurality of holes and at least one stabilizing hold formed therein. The stabilizing hold engage elongated stabilizing member located on the base curve mold to stabilize the mold during monomer polymerization. The front curve top plate also has a plurality of holes formed therein. The top plate holes are in axial alignment with the bottom plate holes thereby providing an opening completely through the carrier when the top plate and the bottom plate are connected to each other. The top plate hole is separated into two sections, a first section and a second section, by a flange. A hollow piston, guided by the flange, travels up and down in the two sections of the top plate hole. The piston is supported by a spring housed in the second section of the top plate hole, which rests upon the top surface of the bottom plate. The top plate also has two top plate stabilizing holes in axial alignment with the bottom plate stabilizing holes. The top plate additionally has at least one channel that houses a locking bar.
The base curve lens mold carrier has a plurality of holes formed therein. The holes formed in the base curve lens mold carrier are divided into a first (or top) section and a second (or bottom) section. The base curve lens mold carrier also has a channel extending from the edge of the first section to the edge of the carrier which provides rotational alignment for the molds by engaging with a protrusion on the outer diameter of the lens mold flange. The base curve lens mold carrier also includes at least one elongated stabilizing member which is in axial alignment with the stabilizing hole formed in the front curve lens mold carrier and which engage with the stabilizing hole to form a stable mold for manufacturing a contact lens. The carriers are transported to various stations within the lens manufacturing process, including lens mold receiving station and lens mold cleaning station.
The carriers of the present invention can be fabricated from various rigid materials including various metal, e.g., steel, stainless steel, aluminum, aluminum alloy, brass and the like. The carriers are highly suitable for carrying ophthalmic lens molds to various stations of a lens manufacturing process, and are highly adapted for automated stations of the process.